Carrier 48NHT024 User Manual

HEATING A COOLING
48N
Packaged Heating/Cooling Units
Installation Instructions
NOTE TO INSTALLER: Leave these instructions, the User's
Manual, and Parts Replacement Guide with the unit after
installation.
A WARNING
Improper installation, adjustment, alteration, service,
maintenance, or use can cause carbon monoxide poison¬
ing, explosion, fire, electric shock, or other occurrences
which may injure you or damage your property. Con¬
sult a qualified installer, service agency, or the gas sup¬
plier for information or assistance. The qualified agency
must use factory authorized kits and accessories when
modifying this unit.
NOTE: The installation of this unit must conform to the
guidelines presented in these unit Installation Instructions.
Read and become familiar with this publication before start¬
ing the installation.
INTRODUCTION
Model 48N Packaged Gas/Electric Unit is fully self-con¬
tained, combination gas heating/electric cooling unit
designed for outdoor installation. Model 48N may be
installed either on a rooftop or ground-level slab. See Fig. 1.
For rooftop downflow applications, an accessory roof¬
mounting curb must be used.
Model 48N Unit meets the California maximum oxides of
nitrogen (No x ) emission regulations.
These units are equipped with an energy-saving, automatic,
intermittent, electric spark ignition system that does not
have a continuously burning pilot. All units are manufac¬
tured with natural gas controls.
These units are designed for a minimum continuous return
air temperature of 60 °F. (dry bulb) or an intermittent opera¬
tion down to 55°F. (dry bulb) such as when used with a
night set back thermostat.
Model 48N is A.G.A. and C.G.A. design-certified. See
Tables 2 thru 7 for the heating input ratings.
These units are factory-charged with R-22 refrigerant.
Installation is simple: connect gas supply, air ducts, high-
and low-voltage wiring, condensate drain, and install a field-
supplied air filter.
All units can be connected into existing duct systems that
are properly sized and designed to handle an airflow of 350
to 450 Cfm per each 12,000 Btuh of rated cooling capacity.
See Tables 2 thru 7 for cooling and heating airflow require¬
ments.
NOTE: When installing any accessory item, see the manu¬
facturer's Installation Instructions packaged with the ac¬
cessory. The Qualified Agency must use factory authorized
kits or accessories when modifying this unit.
Fig. 1 —Model 48N
IMPORTANT—READ BEFORE INSTALLING
1. This installation must conform with all applicable local
and national codes.
2. The power supply (volts, hertz, and phase) must corre¬
spond to that specified on unit rating plate.
3. The electrical supply provided by the utility must be
sufficient to handle load imposed by this unit.
4. Refer to the 48N dimensional drawing for locations of
gas inlet, electrical inlets, condensate drain, duct con¬
nections, and required clearances before setting unit in
place. Figs. 2 and 3.
5. Locate the unit where the vent cap will be a minimum
of 4-ft from openable windows or doors.
6. This installation must conform with local building
codes and with the National Fuel Gas Code ANSI
Z223.1-1984 and Addenda Z223.la-1987 (In Canada,
CAN/CGA B149.1, (2)-M86) or NFPA 54-1984 TIA-54-
84-1. Refer to Provincial and local plumbing or
wastewater codes and other applicable local codes.
7. For outdoor installation on wood flooring or on class A,
B, C roof covering materials.
GENERAL
Model 48N Packaged Gas/Electric Unit has been designed
and tested in accordance with ANSI Z21.47-1987, ARI
Standard 210-81, and ARI Standard 270-84, CAN/CGA-2.3-
M86, CAN 1-2.17-M80, CAN 1-2.21-M85, CSA C22.2 No. 0-
1982, No. 3-1979 and No. 119-M1985. The appliance design
is certified by the American Gas Association (A.G.A.) and
Canadian Gas Association (C.G.A.) for use with natural or
LP (propane) gases with appropriate controls and orifices.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 101 Catalog No. 564-816 Printed in U.S.A. Form 48NT-9SI Pg 1 9-88 Replaces: 48NT-8SI
Book 1
4
Tab la la

Carrier 48NHT024 Specifications

General

Brand	Carrier
Model	48NHT024
Category	Chiller
Language	English

Summary

Introduction to Carrier 48N Units

Critical Installation Precautions

Essential safety and code compliance guidelines for unit installation.

General Unit Information and Standards

Unit Design and Certifications

Details unit design compliance with industry standards and certifications.

Unit Placement and Rigging

Rooftop Installation Guidelines

Specific instructions for mounting the unit on a rooftop.

Ground-Level Installation Base

Requirements for a solid, level pad for ground-level placement.

Condensate Water Management

Unit Venting System Installation

Gas Piping Installation

Duct Connections

Electrical Connections

Preparing Unit for Startup

Heating Section Startup and Adjustments

Cooling Section Startup and Adjustments

Routine Unit Maintenance and Care